Clutch cable adjusting mechanism

ABSTRACT

A clutch cable lever operating system having a cable adjusting mechanism including a clamp for mounting the system on the handlebars of a motorcycle. The clutch cable lever fulcrum mounting flange to allow more or less free travel when the cable operating lever is used. The clutch cable adjusting mechanism is comprised of a coarse sleeve threaded into a cable adjusting cylinder that abuts the end of a cable outer sleeve. A manually adjusted threaded star nut or thumb wheel is fitted in a slot in the cable adjusting cylinder and threads on the coarse threaded sleeve. Rotation of the threaded star nut or thumb wheel incrementally extends or retracts the coarse threaded sleeve abutting the end of cable to adjust the slack that occurs when clutch plates expand due to heat. A resilient washer in an annulus intersecting the threads in the star nut or thumb wheel prevents free movement of the star nut on the coarse threaded sleeve to maintain the adjusted position. The resilient washer prevents free movement of the star nut from an adjusted position which might be caused by vibration during operation of a motorcycle.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to clutch lever systems for motorcycles andsimilar vehicles, and more particularly, relates to a clutch cableadjustment mechanism for motorcycles.

2. Background Information

Lever operated cable systems are used on motorcycles and similarvehicles for operation of clutches. The cable systems used to operateclutches often need adjustment due to temperature related componentexpansions. The clutch is operated by pulling a lever to pull a cableand operate the clutch. Slack in the cable can make operation of theclutch difficult, or prevent operation altogether. In many cases,adjustments can be performed when the vehicle is not in use. However, incertain situations these adjustments can become critical and there is aneed to make adjustments while the vehicle is in motion.

When motorcycles are used for racing, adjustment of the clutch mechanismcan be critical. Motorcycle clutch plates expand under use due to theheat generated. This can cause the clutch lever mechanism to slacken andultimately become almost useless. This, of course, can be a serioussituation if it occurs during a race. The motorcycle operator cannotstop to make an adjustment, and difficulty in operating the clutch cansufficiently slow the motorcycle to result in a loss of time andprobably, the loss of a race. Therefore, it would be advantageous ifadjustments could be made while the motorcycle is in motion.

Presently, adjustment mechanisms for these motorcycles are comprised ofa threaded shaft attached to the end of the cable which is tightened bytightening a nut on the threaded shaft. The nut is then clamped in placewith a second nut to maintain the tension on the cable. However, when acable becomes lose due to excessive heat causing the clutch plates toexpand, there is no way to make these adjustments while the vehicle isin motion.

It is therefore one object of the present invention to provide a clutchcable mechanism adjustment that can be performed while the vehicle is inmotion.

Another object of the present invention is to provide a clutch cableadjustment mechanism having a manually operated star nut to adjust thetension on the clutch cable while a vehicle is in motion.

Still another object of the present invention is to provide a clutchcable adjustment mechanism having universally applicable to allmotorcycles.

Yet another object of the present invention is to provide a clutch cableadjusting mechanism having its free length adjusted by a threaded starnut set by an interval resilient washer to prevent it from freelyrotating.

Still another object of the present invention is to have a clutch cableadjustment mechanism of a star nut with a resilient washer to maintainan adjusted position and prevent movement from vibration.

Yet another object of the present invention is to provide a clutch cableadjusting mechanism having a lever bracket housing large enough indiameter to accept complete motorcycle clutch cable assemblies.

BRIEF DESCRIPTION OF THE INVENTION

The purpose of the present invention is to provide a clutch cableadjusting mechanism that can be easily adjusted while a motorcycle is inmotion.

The clutch cable adjusting mechanism of the present invention iscomprised of a clamp for clamping the clutch cable assembly to thehandlebar of a motorcycle having a clutch operating lever mounted on theclamp. The clutch operating lever is mounted on the clamp by a flangewhich provides a fulcrum. The fulcrum on the end of the flange, isattached to the handlebar clamp by a threaded bolt inserted through abushing in the lever. The fulcrum mounting hole in the flange providesthe maximum travel of the clutch cable operating lever and applies themost travel on the clutch cable.

A clutch cable adjusting mechanism is provided by a lever brackethousing and a cable adjusting cylinder mounted on the handlebar clampthat is large enough in diameter to accept the complete motorcycleclutch cable assembly. The cable adjusting mechanism features a coursethreaded sleeve inserted in the cable adjusting cylinder. The coarsethreaded sleeve is long enough to accommodate substantially allmotorcycle clutch cables to make the device universally applicable.

The clutch cable is a coaxial cable having an inner steel cable and anouter cable sleeve. The inner clutch cable passes through the threadedsleeve and cable adjusting cylinder. A cable barrel, clamped on the endof the cable, seats in a notch in the operating lever to securely holdand operate the cable.

The outer cable sleeve has a sleeve cap seated in a socket in theinterior of the coarse threaded sleeve against a shoulder. The coarsethreaded sleeve has a longitudinal slot for receiving a guide screw toprevent the sleeve from turning when adjustments are being made to thecable.

Cable adjustments are performed by a star nut or thumb wheel threaded onthe coarse threaded sleeve. Rotation of the threaded star nut extends orretracts the coarse threaded sleeve to adjust the tension on the outercable of the clutch to adjust for excessive slack. The threaded star nuthas an interior resilient washer in the threads which prevents thethreaded star nut from freely rotating after an adjustment is made. Useof such resilient washers of members inside nuts has long been known.Such devices are used as lock nuts to prevent them from loosening afterinstallation. Such devices are disclosed in U.S. Pat. No. 180,064 issuedJul. 18, 1876, U.S. Pat. No. 184,835 issued Nov. 28, 1876, U.S. Pat. No.4,749,320 issued Jun. 7, 1988 and U.S. Pat. No. 5,584,210 issued Dec.17, 1996 all teach the use of a resilient member in the threads of a nutto lock the nut in place after installation. Use of such a device in amanually adjustable star nut or thumb wheel for making and settingadjustments "on the fly" is a unique application of the principle. Itsolves the problem of clutch adjustments during a race that normallycannot be made at all.

To take up slack in the cable, the threaded star nut is manually rotatedby the rider to adjust the cable and take up slack. Each adjustment isset by resilient washer that prevents movement from the set positionthat might be caused by vibrations when the motorcycle is running. Thiscan be done while the motorcycle is in motion to compensate forexpansion of motorcycle clutch plates under strenuous use such as theheat generated during a race.

The above and other novel features of the invention will be more fullyunderstood from the following detailed description and the accompanyingdrawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation of the clutch lever and cable adjustingmechanism according to the invention.

FIG. 2 is a top view of the clutch operating lever and cable adjustingmechanism.

FIG. 3 is a sectional view taken at 3--3 of FIG. 2.

FIG. 4 is a sectional view, similar to FIG. 3, illustrating operation ofthe invention.

FIG. 5 is a sectional view taken at 5--5 of FIG. 3.

FIG. 6 is an exploded view of the clutch cable adjusting mechanismaccording to the invention.

DETAILED DESCRIPTION OF THE INVENTION

A clutch lever operating system with a cable adjusting mechanism isillustrated in FIG. 1. A clutch lever operating mechanism is comprisedof clutch operating lever 10 and handlebar clamp 12 for clamping theclutch lever operating system on handlebar 14 with bolt 16. The cablelever operating system also includes cable lever 18 and cable adjustingmechanism 20 comprised of threaded sleeve 24 and star nut or thumb wheel26 which will be described in greater detail hereinafter. Cableoperating lever 10 is mounted on clamp 12 by threaded screw 22 as willbe described in greater detail hereinafter.

Clutch cable adjusting mechanism 20 includes coarse threaded sleeve 24and a thumb operated star nut 26 receiving coaxial clutch cable 28comprised of inner cable 30 and other cable sleeve 32. Inner cable 30 issecured to cable operating lever 10 while outer cable sleeve 32 issecured to coarse threaded sleeve 24 for adjusting the slack in thecable by cable adjusting threaded star nut 26 as will be described ingreater detail hereinafter.

The mounting system for cable operating lever 10 and clutch cableadjusting mechanism 20 is shown in greater detail in FIGS. 3 and 4.Clutch operating lever 10 has lever flange 33 providing a mountingsystem. Flange 33 fits into slot 34 in a fulcrum housing 35 formed onhandlebar clamp 12. Fulcrum housing 35 has threaded holes on either sidefor receiving threaded pin or screw 22 passing through bushing 36mounted in hole 37 on lever flange 33.

Clutch cable 28 is secured to cable operating lever 10 by cable barrel42 mounted on inner cable 30. Cable barrel 42 is securely crimped at 44onto the end of steel cable 32. Cable barrel 42 is then seated in notch43 provided in cable lever 10. Operation of lever 10 applies tension toclutch cable 28.

A unique cable adjusting mechanism is also illustrated in FIGS. 3through 5. Cable adjusting mechanism 20 is comprised of cable adjustingcylinder 46 formed on cable lever mounting bracket 18 for receiving thecable adjusting components. Cable adjusting cylinder 46 is large enoughin diameter to accept the complete motorcycle clutch adjusting cableassembly. Cable adjusting cylinder 46 receives-coarse threaded sleeve 24and star nut 26 inserted in slot 27 threaded over coarse threaded sleeve24. Outer cable sleeve 32 fits into coarse threaded sleeve 24 and isseated against shoulder 50 near the inner end of socket 49 in coarsethreaded sleeve 24. Slack in cable 28 is taken up by moving coarsethreaded sleeve 24 out of, or into cable adjusting cylinder 46 as willbe described in greater detail hereinafter.

Coarse threaded sleeve 24 has a lengthwise slot 52 which can be seenmore clearly in FIG. 6. A guide screw 54 is threaded through hole 56 incable adjusting cylinder 46 to engage lengthwise slot 52 to preventcoarse threaded sleeve 24 from turning when adjustments to cable 28 arebeing made. Preferably, coarse threaded sleeve 24 is made long enough toaccommodate the free length of most motorcycle clutch cables. Thisallows the cable adjusting mechanism to be universally adaptable toalmost all existing motorcycles.

Adjustments are made to take up slack in cable 38 with threaded star nut26 which is threaded on coarse threaded sleeve 24. Manual rotation ofstar nut 26 extends or retracts coarse threaded sleeve 24 in or out ofclutch cable adjusting cylinder 46. Extending the coarse threaded sleeve24 increases cable tension to take up slack while retracting it loosensthe cable.

Threaded star nut or thumb wheel 26 includes resilient washer 58 inannulus 60 in the threads of the star nut. The free length of cable 28is adjusted by manual rotation of star nut or thumb wheel toincrementally advance or retract sleeve 24 with cable 28 attached.

The unique clutch cable adjusting mechanism allows adjusting the freetravel of cable 28 while a motorcycle is in motion. This alleviatesdifficulties in operating a clutch when the clutch plates expand fromthe heat under excessive use in off-road racing. Star nut or thumb wheel26 can be rotated manually to make precise incremental adjustments. Withresilient washer 58 inside star wheel 26 free movement after incrementaladjustments are set is prevented.

The clutch cable adjusting mechanism also eliminates the need to stopand make adjustments as in present systems. With present systems alocking nut has to be released and then the adjustments made. Thisoperation cannot be performed while a motorcycle is in motion. Themanual incremental adjustment and star nut for adjusting the travel ofcoarse threaded sleeve 24 will adjust the free travel of cable 28 takingup any slack in the cable as it occurs during a race. The resilientwasher 58 in the threads of star nut 26 prevents free movement afteradjustment from vibration of the motorcycle during opportune. Eachincremental adjustment is set and maintained by preventing free movementof star nut and coarse threaded sleeve 24.

Thus, there has been described a unique clutch cable lever operatingsystem and a cable adjusting mechanism that allows adjustments to bemade while a motorcycle is in motion. The clutch cable lever operatingsystem has fulcrum mounting system for secure mounting on the handlebarof a motorcycle. The cable adjusting mechanism, having a coarse threadedsleeve and a star nut or thumb wheel threaded nut with an intervalresilient washer inside the threads, allow adjustments to be made whilethe motorcycle or like vehicle is in motion. Manual rotation of thethreaded star nut or thumb wheel, while in motion, adjusts the freetravel or slack in a cable and the incremental adjusted position ismaintained by the resilient washer inside the threads. The cable leveroperating system and clutch cable adjusting mechanism are designed withunique features that make the entire system universally adaptable tomost motorcycles or like vehicles.

This invention is not to be limited by the embodiment shown in thedrawings and described in the description which is given by way ofexample and not of limitation, but only in accordance with the scope ofthe appended claims.

What is claimed is:
 1. A clutch cable adjusting mechanism comprising;aclutch cable operating lever; threaded cable adjusting cylinder; acoarse threaded sleeve threaded into said cylinder receiving one end ofsaid clutch cable; claim means for clamping said cable adjustingmechanism on a handlebar, said cable adjusting cylinder being integrallyformed in said clamp means; said coarse threaded sleeve comprising athreaded hollow sleeve having an interior shoulder at one end ofabutting an end of a clutch cable, rotation preventing means forpreventing said coarse threaded sleeve from rotating when adjustmentsare being made, said coarse threaded sleeve has a length selected toaccommodate a wide of clutch cables; said rotation prevention meanscomprising a lengthwise slot in said threaded hollow sleeve, and a guidescrew engaging said lengthwise slot to prevent said threaded sleeve fromrotating while allowing axial movement; manual adjusting means formanual incremental adjusting said clutch cable by extending orretracting said coarse threaded sleeve from said threaded cableadjusting cylinder while in motion.
 2. The cable adjusting mechanismaccording to claim 1 including free movement prevention means forsetting said manual adjusting means at each incrementally adjustedposition.
 3. The cable adjusting mechanism according to claim 2 in whichsaid free movement preventing means comprises resilient means insidesaid manual adjusting means for incrementally adjusting and holding saidmanual adjusting means in each adjusted position.
 4. The cable adjustingmechanism according to claim 3 in which said manual adjusting meanscomprises a star nut threaded on said coarse threaded sleeve; andannulus in the threads of said star nut and a resilient washer in saidannulus.